Method for performing exo-atmospheric missile&#39;s interception trial

ABSTRACT

An inflatable dummy target comprising a chassis of inflatable ducts wrapped with a sheet. The chassis of inflatable ducts can include one or more ring shaped ducts and one or more elongate ducts. The chassis can include at least two ring shaped ducts interconnected by one or more elongate ducts. The dummy target can include several attached axi-symmetrical sections, each section have a chassis of inflatable ducts. Each section can be conical, frustoconical or cylindrical, thereby achieving a concave or convex dummy target geometry.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from Israeli Patent Application No.242428, filed on Nov. 3, 2015, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

This invention is in the field of performing exo-atmospheric missile'sinterception trials.

BACKGROUND OF THE INVENTION

Ground to Ground (GTG) missiles have become an efficient weapon whichcan cause significant damage to military and civilian infra-structures,and thereby they serve as a strategic tool in favor of states whichattack their enemies (either offensively or defensively as a result ofan attack originated by the enemy). In light of this ever increasingthreat, an anti missile technology has been developed, such as the plandesignated “star war”, the “Arrow” anti-missile technology (deployed andused by the Israel Defense Forces) and others. The anti missiletechnology, such as the Arrow system is capable of tracking the oncomingground to ground missiles and launch e.g. from a protected territory ananti-missile missile (AMM) (referred to also as kill vehicle—KV) whichflies along a flight trajectory which substantially collides with thatof the oncoming threat. The anti-missile missile approaches the oncomingthreat (at a safe distance from the protected territory) and destroys itby using the hit to kill method or by activating an appropriate killwarhead which destroys at least the active warhead of the threat andthereby prevents the arrival of the threat (or damaging debris) to theprotected territory.

In the last few years a wide range of new threats have been introducedsuch as the Shihab 3, Sihab 2000, Zelzal, Scud D and others, each ofwhich having its unique flight characteristics, such as missilegeometry, flight dynamics, IR and or RF signature, etc. The differentflight characteristics of each threat impose a new challenge for killvehicles, which should be upgraded to handle also new threats.

In order to assure proper operation in real life scenarios, the upgradedkill vehicle should be tested against a simulated threat having flightcharacteristics that resemble that of the real threat. Thus, forexample, with the introduction of the Shihab 3 and after obtainingsufficient intelligent information as to the missile's flightcharacteristics, the kill vehicle should be retrofitted in order to dulyhandle also this newly introduced threat. In order to validate theefficiency of the kill vehicle against the threat in a real-lifescenario, it must undergo field experiments in which it is launched andattempts to intercept the threat. However, typically a country whichdevelops an arsenal of KVs such as Israel, does not have access to areal GTG missile (in the latter example, Israel is not likely to have atits disposal a sample Iranian Shihab 3) and accordingly thetechnological challenge is not only to duly retrofit the KV, but also todevelop a dummy threat which simulates the flight characteristics of theGTG missile. The latter is normally a costly and long procedure whichnot only poses financial constraint on the defense project, but alsoextends the turnkey date, since it normally takes a few years to developa dummy missile that has exactly the same flight characteristics as thatof the GTG missile. By the time that the KV has been successfullyretrofitted and tested against the newly introduced threats, new threatsmay emerge that have not, as yet, been adequately addressed. Thedefending state is thus exposed to absorb significant damages due to thefact that the KV is not adapted (and duly tested) to destroy newlyintroduced threats.

It is also known that the destruction of a GTG missile before it hitsfriendly territory is a difficult task, considering the very highrelative velocities between the KV and the GTG missile. The killduration is thus very short and should be viewed accurately in order todetermine whether the warhead portion of the GTG missile has beendestroyed. The very short duration during which the hit occurs, as wellas the far distance from a ground station (considering that theinterception is performed Exo-Atmospheric), poses a significantchallenge on tracking means for providing high quality kill assessment.

There is thus a need in the art to provide for a technique forperforming Exo-Atmospheric missile's interception trials which can beapplicable shortly after introducing of new threats and whichsignificantly simplify (in terms of cost and time) the procedure ofdeveloping a dummy threat that emulates the flight characteristics ofthe GTG missile.

There is a further need in the art to provide for a method which willfacilitate a high quality kill assessment of the interception.

SUMMARY OF THE INVENTION

In accordance with an embodiment of the invention there is provided aninflatable dummy target fittable into a carrier missile capable of beingreleased from the carrier missile during exo-atmospheric flight; uponrelease, the dummy target or portion thereof is capable of beinginflated and manifest characteristics that resemble GTG missilecharacteristics, wherein said GTG missile characteristics include IRsignature, RF signature and GTG missile geometry.

In accordance with an embodiment of the invention there is furtherprovided an inflatable dummy target fittable into a carrier missilecapable of being released from the carrier missile duringexo-atmospheric flight; upon release, the dummy target or portionthereof is capable of being inflated and manifesting exo-atmosphericflight dynamics that resemble GTG missile exo-atmospheric flightdynamics.

In accordance with an embodiment of the invention there is still furtherprovided a carrier missile accommodating at least one inflatable dummytarget, each dummy target capable of being released from the carriermissile during exo-atmospheric flight; upon release, the dummy target orportion thereof is capable of being inflated and manifestingcharacteristics that resemble GTG missile characteristics, wherein saidGTG missile characteristics include IR signature, RF signature and GTGmissile geometry.

In accordance with an embodiment of the invention there is still furtherprovided a carrier missile accommodating at least one inflatable dummytarget, each dummy target capable of being released from the carriermissile during exo-atmospheric flight; upon release, the dummy target orportion thereof is capable of being inflated and manifestingcharacteristics that resemble GTG missile characteristics, wherein saidGTG missile characteristics include exo-atmospheric flight dynamics.

In accordance with an embodiment of the invention there is still furtherprovided a method for generating dummy target characteristics thatresemble (GTG) missile characteristics, comprising:

-   -   (a) releasing an inflatable dummy target from a carrier missile;    -   (b) inflating said dummy target or portion thereof using gas,        thereby manifesting dummy target geometry characteristics that        resemble the GTG missile characteristics, and whereby the dummy        target's characteristics manifest RF signature that resemble        missile RF signature and whereby dummy target's characteristics        manifests IR signature that resembles IR signature of the GTG

In accordance with an embodiment of the invention there is still furtherprovided a method for generating dummy target characteristics thatresemble (GTG) missile characteristics, comprising:

releasing an inflatable dummy target from a carrier missile; inflatingsaid dummy target or portion thereof using gas; and releasing gasthrough at least one nozzle that is fitted in the dummy targetmanifesting exo-atmospheric flight dynamics that resembleexo-atmospheric flight dynamics of a GTG missile.

In accordance with an embodiment of the invention there is still furtherprovided an inflatable dummy target fittable into a carrier missilecapable of being released in a wrapped form from the carrier missileduring exo-atmospheric flight; upon release, the dummy target or portionthereof is capable of being inflated and manifesting exo-atmosphericflight dynamics that resemble GTG missile exo-atmospheric flightdynamics, whereby said dummy target exo-atmospheric flight dynamics areachieved in said inflated form notwithstanding of initial uncontrolledperturbations of the dummy target in a wrapped form.

In accordance with an embodiment of the invention there is still furtherprovided a method for performing exo-atmospheric Ground-to-Groundmissile's interception trial, comprising:

-   -   (a) launching a carrier accommodating at least one dummy target;    -   (b) launching an interceptor for exo-atmospheric interception of        the dummy target;    -   (c) releasing an inflatable dummy target from a carrier missile;    -   (d) inflating said dummy target or portion thereof, the dummy        target has characteristics that resemble GTG missile        characteristics;    -   (e) re-routing a flight trajectory of the dummy target during        releasing from the carrier for at least (i) facilitate sensing        of interception during the END GAME, (ii) assuring that the        carrier being substantially out of the field of view of the        interceptor during the homing stage and the END-GAME if it is        required by interception scenario, and (iii) assuring that the        carrier being substantially in the field of view of the        interceptor during the homing stage and the END-GAME at the        pre-defined location relative to dummy target if it is required        by interception scenario;    -   (f) sensing the interception process;    -   (g) communicating the sensed data.

In accordance with an embodiment of the invention there is still furtherprovided a method for simplifying exo-atmospheric Ground-to-Ground (GTG)missile's interception trial, comprising:

-   -   (a) providing at least one dummy target that is manufacturable        in considerable simpler manufacturing process than a GTG        missile, and capable of manifesting characteristics that        resemble characteristics of the GTG missile;    -   (b) providing a common carrier missile capable of accommodating        at least one dummy target irrespective of the characteristics        thereof;

whereby said common carrier missile is capable of being launched andbeing configured to release at least one dummy target at selectedexo-atmospheric location, for testing the ability of an interceptormissile to intercept said dummy target at exo-atmospheric interceptionpoint, thereby testing the interceptor's operational feasibility todestroy the GTG missile.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, a preferred embodiment will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 illustrates a sample dummy target interception scenario, inaccordance with embodiments of the invention;

FIG. 2A illustrates a flow diagram of a sequence of operation forproviding dummy target interception, in accordance with certainembodiments of the invention;

FIG. 2B, illustrates schematically a re-routing technique in accordancewith certain embodiments of the invention;

FIG. 3A illustrates schematically a dummy target releasing mechanism, inaccordance with an embodiment of the invention;

FIG. 3B illustrates schematically a flowchart of the operational stagesfor releasing and activating a dummy target, in accordance with certainembodiments of the invention;

FIGS. 4A-C illustrate schematically a more detailed dummy targetreleasing mechanism, in accordance with an embodiment of the invention;

FIGS. 5A-B illustrate schematically a dummy target in wrapped andinflated forms respectively, in accordance with an embodiment of theinvention.

FIGS. 6A-B illustrate schematically front and side views of a dummytarget in accordance with an embodiment of the invention;

FIG. 6C illustrates schematically an enlarged view of a nozzle fitted ina dummy target, in accordance with an embodiment of the invention;

FIGS. 7A-B illustrate schematically nozzle shapes fitted in a dummytarget, in accordance with an embodiment of the invention;

FIGS. 8A-B illustrate schematically respective front and side views of adummy target, serving for explaining dynamic equations, in accordancewith an embodiment of the invention;

FIG. 9A-B illustrate a set of equations serving for explaining thedynamics exo-atmospheric flight characteristics of a dummy target, inaccordance with a certain embodiment of the invention;

FIG. 10A-D illustrate schematically a dummy target in accordance withanother embodiment of the invention;

FIG. 11A-B illustrate schematically means for generating appropriateflight dynamics in a dummy target, in accordance with certainembodiments of the invention; and

FIG. 12 illustrates schematically a IR signature activation curve, inaccordance with certain embodiments of the invention.

FIG. 13A-E illustrate schematically inflatable dummy targets withdifferent geometry shapes including both concave and convex shapes, inaccordance with certain embodiments of the invention.

FIG. 14A-D illustrate examples of inflatable chassis installed intoinflatable dummy targets, in accordance with certain embodiments of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions, utilizing terms such as, “processing”, “computing”,“calculating”, “determining”, or the like, refer to the action and/orprocesses of a computer or computing system, or processor or similarelectronic computing device, that manipulate and/or transform datarepresented as physical, such as electronic, quantities within thecomputing system's registers and/or memories into other data, similarlyrepresented as physical quantities within the computing system'smemories, registers or other such information storage, transmission ordisplay devices.

Before moving on, it should be noted that in the context of theinvention whenever the term ground to ground (GTG) missile is referredto, it likewise applies to reentry vehicle (RV) e.g. in the case ofmulti stages missiles.

Note also that in the case of an axi-symmetric dummy target, anyreference to the pitch axis likewise applies to the yaw axis. Forexample, pitch angular velocity likewise applies to yaw angularvelocity.

Bearing this in mind, attention is first drawn to FIG. 1 illustratingschematically a sample dummy target interception scenario, in accordancewith an embodiment of the invention. As shown, a carrier missile 11 islaunched and flies along exo-atmospheric flight trajectory 12. At acertain post boost stage, the motor is separated and discarded (notshown) and the remaining portion of the carrier continues to fly,leaving the atmosphere, and proceeds along an exo-atmospheric flighttrajectory. Also shown is an anti-missile missile (KV) (referred to alsoas interceptor) 13 having an associated radar system (not shown), beingconfigured to track an oncoming GTG missile (in this case the dummytarget) and invoke a launch command to the interceptor. The latter fliesalong an exo-atmospheric flight trajectory 14 that is designated to acollision course whereupon the interceptor substantially collides withthe oncoming GTG missile (in this case the dummy target).

Note that there are two main killing mechanisms used by targetinterceptions by interceptors well known from prior art:

-   -   Hit to kill (using of interceptor body for GTG warhead        destroying) used typically, although not necessarily, in        exo-atmospheric kill scenes.    -   Activation killing warhead at a close proximity to the dummy        target, a kill warhead that is fitted in the interceptor is        invoked, for destroying at least the warhead of the GTG missile,        thereby rendering it inoperable. In this case the kill warhead        is designated to kill the dummy target. This technique is used        typically, although not necessarily, in endo-atmospheric kill        scenes.

Choosing of killing method depends on many technical and otheruncertainties like typical miss distance at interception, sensitivity oflethality on incidence angle, target characteristics, uncertaintiesincluding the exact place of GTG warhead/warhead activator etc. Thetechnique according to the invention is suitable for both types ofinterceptors killing mechanisms. The only additional limitation forsuccess kill assessment performance in the case of killing warheadmechanisms is that the carrier should be away from the interceptor'swarhead fragments beam.

As specified above, in order to assure proper operation in a real lifescenario, the KV should be tested against a missile having flightcharacteristics that resemble that of the real GTG missile threat.Providing an accurate simulated threat of the kind specified normallyinvolves long and costly design and manufacturing procedures which poseinherent limitations that were discussed in detail above.

Thus, in accordance with the invention, there is provided a method forperforming exo-atmospheric Ground-to-Ground missiles interceptiontrials. To this end, in accordance with certain embodiments, a carrier11 that accommodated at least one dummy target (not shown in FIG. 1) islaunched. At a certain location 15, an inflatable dummy target isreleased from a carrier missile, and upon release, the dummy target isinflated and manifests characteristics that resemble those of a GTGmissile, all as will be explained in greater detail below. Aninterceptor 13 is launched for exo-atmospheric interception of the dummytarget. The dummy target 16 continues to fly along the specified flighttrajectory (or in accordance with certain embodiments along re-routedflight trajectory 17 as shown in FIG. 1). Note that the reason ofre-routing the flight trajectory of the dummy target will be discussedin greater detail below. As will be further discussed below, the dummytarget has a simple structure and can be easily manufactured to havecharacteristics such as IR signature, RF signature, geometry and/ordynamics that resemble those of the GTG missile, in considerable simplerdesign and manufacturing process than those of simulation missiles asused in accordance with the prior art.

Reverting now to FIG. 1, upon release of the dummy target, the flighttrajectory of the carrier missile may be re-routed 18 so as tofacilitate sensing of interception process during the homing stagewherein the interceptor 13 attempts to intercept the dummy target atinterception point 19. Note also that in accordance with certainembodiments the trajectory of the carrier may be re-routed to ensurethat the carrier is substantially out of the field of view of theinterceptor during the END GAME if it is required by interceptionscenario. Otherwise the carrier may be used as an additional object inan interceptor's field of view if that is required by testing theinterception scenario (for example for validation of discriminationalgorithm etc.)

After having sensed the kill scene, e.g. by acquiring images of theinterception process, the sensed data can be communicated, for example,to a remote ground station, for, say assessing the quality of thekill—determining of the key kill parameters like miss distance,incidence angle etc.

The interception scenario that was described in FIG. 1 is by no meansbinding. For example, the invention is not bound by a carrier of thekind specified, the interception route of the interceptor or the dummytarget and the manner of sensing the interception process, etc.

Having described a typical interception scenario, there follows adescription (with reference to FIG. 2A) of a sequence of operations forproviding dummy target interception, in accordance with certainembodiments of the invention. Thus, at stage 21 a, a carrier thataccommodated at least one dummy target is launched. There follows astaging phase 21 b and sustainer ignition stage 21 c for entering thecarrier to a desired exo-atmospheric trajectory 21 d. Note that in 21 dthere is also a re-routing of the carrier's trajectory whenevernecessary. Next, at a certain location in the exo-atmosphere, aninflatable dummy target is released 22 from a carrier missile (see also15 at FIG. 1).

Next (23), the dummy target is inflated such that it has RF signaturegeometry and other flight characteristics that resemble those of a GTGmissile of interest. At this stage 24, the flight trajectory of thedummy target is re-routed (see, for example, 17 in FIG. 1) whilst thecarrier keeps tracking the dummy target 25. The re-routing achieves atleast the following: (i) the new route deviates from the flighttrajectory of the carrier missile (see, for example, 18 in FIG. 1) so asto facilitate sensing of kill scene when the interceptor attempts tointercept the dummy target during the END GAME (for example,exo-atmospheric site 19 depicted in FIG. 1).

Note that in accordance with certain embodiments, the re-routing of theflight trajectory of the carrier is designed accordingly to theinterception test objectives:

-   -   to assure that the carrier being substantially out of the field        of view of the interceptor during the homing stage 19. This        killing scenario is more suitable to non-separate target        interception scenarios where the carrier does not form part of        the intercepted target. In other words, the interceptor is aimed        towards the inflatable dummy target only. In this case it may be        desired to retain the carrier outside the FOY of the interceptor        during the homing stage, since otherwise the interceptor may        home onto the carrier instead of the designated dummy target of        interest. The dummy target, as may be recalled, imitates the        real target.    -   to assure that the carrier is in the field of view of the        interceptor at the proper distance for example in case of a        multistage target scenario. This scenario is suitable in a        situation where the interceptor views the various stages of the        target and should discern what the target of interest is. Thus,        for example, the interceptor should view (during homing stage)        the dummy target (imitating the real target) and the carrier and        decide that the real threat is the dummy target, therefore        homing onto the latter and ignoring the carrier which does not        pose a real threat. Note that the re-routing of the flight        trajectory of the carrier may be performed for meeting also        other requirements, all as required and appropriate depending        upon the particular application.

Reverting to FIG. 2A, while the dummy target is re-routed and thecarrier tracks the dummy target (24 and 25, respectively), the groundstation (which is in charge of the launching of the interceptor)acquires the dummy target 26 and applies defense program planning 27 forlaunching the interceptor missile 28. The latter is launched 29 a,undergoes staging 29 b, as well as sustainer ignition 29 c and commencesdummy target acquisition sequence 29 d (only after the dummy target hasobtained the desired target characteristics, e.g. it acquired thedesired IR signature and to this end, the dummy target skin is heated201 (as will be explained in greater detail below with reference to FIG.12).

Simultaneously, the ground control controls the interception sequence202.

Next, the carrier senses the interception point. The sensing can beachieved by, e.g. image acquisition means attached to the carrier or byway of another non-limiting example by image acquisition means that arereleased from the carrier for acquiring a sky view of the interceptionscene at the interception point, all as will be described in greaterdetail below. The interceptor now homes onto the dummy target 203 andintercepts the dummy target 204 at the interception point. The dummytarget is destroyed 205, and the carrier which senses the interceptionpoint performs kill assessment 206 and the sensed data is communicatede.g. to a remote ground station 207 which is capable of assessing thesuccess extent of the interception 208. In accordance with certainembodiments, the ability to acquire a sky view of the interception pointfrom a proximate location (say from the carrier or from acquisitionmeans released therefrom) constitutes a significant advantage comparedto a situation where the view of the interception scene is obtained froma remote location such as a ground station. Obtaining a sky view from ashorter distance allows a clear view of the kill scene which mayfacilitate accurate assessment of the interception and, in case ofpartial or full failure, applying the desired modifications in order toachieve successful results in subsequent trials.

Reverting now to FIG. 2A, after intercepting the dummy target, itsdebris enter the atmosphere and are burned 209. The carrier (havingaccomplished its mission) is guided 210 to a prior planned falling area(e.g. in order not to fall onto friendly territory), as will beexplained in greater detail below and likewise, the interceptor isguided to a pre-planned falling area 211 (as will be explained ingreater detail below).

Bearing this in mind, attention is drawn to FIG. 2B, illustratingschematically a re-routing technique in accordance with certainembodiments of the invention. Thus, at the release location (221), thedummy target flies in velocity V₁ at a direction depicted schematicallyby vector V₁ (222). There is a need to confer a small lateral velocitycomponent Δv (223) (Δv<<V₁) which necessary entails deviation of thecarrier missile from direction (222) to a re-routed direction designatedby vector V₂ (224). The lateral velocity component can be realized, e.g.by activating a small rocket or say activating other techniques likepyro technique charge, pneumatic or mechanical energy sources etc. (notshown), all as known per se. The velocity component Δv is determined togive rise to a re-routed flight trajectory of the carrier 225 which, asspecified above, achieves at least the following: (i) the new routedeviates from the flight trajectory of the dummy target (226) so as tofacilitate sensing of interception scene when the interceptor 227attempts to intercept the dummy target at the interception point (228).As also specified above, in accordance with certain embodiments, there-routing of the flight trajectory of the carrier is designed accordingto the interception test objectives.

As may be recalled, the dummy target has substantially the samecharacteristics as those of the simulated GTG missile, and accordingly,if the interceptor succeeds in destroying the dummy target, then thelikelihood of successful interception of a real GTG threat by the sametype of interceptor, significantly increases.

In accordance with certain embodiments, the Exo-Atmospheric missile'sinterception trial allows to destroy in a controlled fashion both theinterceptor and the carrier missiles after the interception event. Thisis shown schematically in 101 of FIG. 1, illustrating the falling trailof the interceptor and 102 illustrating the falling trail of thecarrier. Assuming that the interception point is selected to be in anunpopulated area (or the sea), both missiles (interceptor and carrier)should sink into the deep sea after the interception test. It should benoted that according to the proposed method of interception test:

-   -   After the interception, there remain two controllable missiles        (carrier and interceptor) and parts of the dummy target (in case        of successful test) or unharmed dummy target (in case of an        unsuccessful test).    -   In both cases the dummy target or its parts will be burned        during re-entry into the earth's atmosphere and will not reach        the earth's surface.    -   Unharmed and fully controllable carrier missiles could be led        exactly into the appropriate area in the sea.    -   Interceptor, after colliding with dummy target, may be lightly        damaged and destroyed by fully controlled self destruction        mechanisms.    -   None of the noted bodies produce dangerous high energy        uncontrolled debris during interception

In accordance with certain other embodiments, there is a need tosimulate a GTG missile that is likely to be launched from a far distance(e.g. from an enemy state). To this end, the carrier should have beenlaunched from a trial territory being of substantially similar distanceto what would have been the distance, had the real GTG been launched andin this case the carrier would fly along the longer flight trajectory.Similar to the GTG missile, the dummy target (which simulates the GTGmissile) is likely to fly in a similar flight trajectory as that of thereal threat, thus simulating a real threat scenario. However, forcertain countries (for instance, Israel) which would desire to performthe interception trial in accordance with the teachings of theinvention, there is no access to such far territory for launching thecarrier therefrom. There is thus a need to launch the carrier missilefrom a shorter distance (giving rise to shorter flight trajectory),however achieving a flight trajectory that resembles the long one whicha GTG missile would have flown, had it been launched from the fartherenemy territory. Thus, in accordance with certain embodiments, and asillustrated by way of non-limiting example in FIG. 1, the carrier 11 islaunched from location D2 (giving rise to a distance of D2−D1 from theinterceptor 13 launching location D1). However, it would have beendesired to launch the carrier from location D3 since the distance D3−D1(>D2−D1) is the actual distance from which a real threat would have beenlaunched, had the enemy committed an act of war. There is thus a need,in accordance with certain embodiments, to cope with the specifiedlimitation where there is no accessible territory at location D3 andnevertheless achieving a flight trajectory that simulates that of a realthreat. Thus, in accordance with certain embodiments the carrier islaunched from D2, however, when the dummy target is released, it isre-routed to a trajectory having characteristics similar to the longerflight trajectory (i.e. had the carrier been launched from D3). This isillustrated by back tracking the re-routed flight trajectory of dummytarget 16 (see trajectory 103 marked in dashed line) to a virtuallaunching point D3. Of course, D1, D2 and D3 are provided by way ofexample only and the dummy target can be directed to a different desiredtrajectory depending on the desired virtual launching location. There-routed flight trajectory of the dummy target thus simulates a launchof the dummy target from a further distance than the actual launchingpoint of the carrier.

Having described a typical dummy target interception scenario and asequence of operational stages in accordance with certain embodiments ofthe invention, there follows a description that pertains to the dummytarget structure and operation in accordance with certain embodiments ofthe invention. FIG. 3A illustrates schematically a dummy targetreleasing mechanism, in accordance with an embodiment of the invention.As shown, the carrier 31 accommodates dummy targets 32 and 23 that arelocated in a designated compartment inside the missile. As will beexplained in greater detail below, the dummy targets are stored in thecompartment in a wrapped form and are inflated upon release.

Turning now to FIG. 3B, there is shown a flowchart of the operationalstages for releasing and activating a dummy target, in accordance withcertain embodiments of the invention. Thus, when the missile arrives ata given location in space (e.g. 15, as described with reference to FIG.1, above), 301 a known per se activation means are invoked (e.g.activating pyro technique charge, pneumatic or mechanical energy sourcesetc.), and the dummy targets are released to the space 302. Uponrelease, the dummy targets are inflated, using, say, air that ispressurized by a pressure vessel or a gas generator 303 (as described ingreater detail below). The air inflates the dummy target 304. The dummytarget is now ready 305 and flies in a designated file trajectory (e.g.17), as described with reference to FIG. 1 above.

Turning now to FIGS. 4A-C, they illustrate schematically a more detaileddummy target releasing mechanism, in accordance with certain embodimentof the invention. Thus, the dummy targets are accommodated in designatedcompartment(s) (in this example compartments 42 and 43 of carriermissile 41, such that each compartment accommodates one dummy target ina wrapped form. Upon release, say by invocation of an air bag 44, thedummy target is ejected to space and is filled with air generated by apressure vessel or a gas generator and transformed (in its inflatedstate) to an object having geometry that resembles that of the missile45, as shown in FIG. 4B. As specified above with reference to FIG. 1,the release occurs at a desired stage.

Another case of dummy target assembling and releasing is described inFIG. 4C. The carrier missile 401 flight starts in e.g. configurationwith two full solid motors, 402, 403. After the end of the boost stage,the missile separation e.g. out of space, is performed. The first stage404 with the empty first solid motor 405 and the shroud 408 areseparated from the second stage 406 with the full second stage motor407. The second stage is accelerated by second stage motor 407 andcoincides with the desired trajectory 103 of FIG. 1. At this point 409the second stage motor 407 of the second carrier stage 406 is empty. Thedummy target skin 411 is inflated around the carrier 406. The carriersteering mechanism (ACS, 413) can be used for accomplishing rotating thedummy target about the roll axis 412. By this embodiment, the secondstage carrier body can simulate the warhead of the real enemy re-entryvehicle. The interception of such a kind of target is not totally freefrom the debris clouds, but the target debris cloud is significantlyreduced in comparison to a regular target. The additional advantage ofsuch configuration is a positive validation of hitting accuracy andlethality (the interceptor should not only hit the target skin, butshould do so in the limited area of the target's warhead).

More specifically, by this embodiment, the rigid second carrier stagebody 406 simulates a warhead, e.g. a rigid compartment 415 accommodatingdifferent kinds of warheads. The interceptor is thus required topenetrate not only the external surface of the dummy target, but ratheralso the internal rigid structure 406 that simulates the warheadcompartment. In accordance with certain embodiments, known per se meanscan be utilized to assess whether the rigid structure has beendestroyed. Typically although not necessarily, the inflation of a dummytarget portion around the second stage rigid structure 406 is feasibleby virtue of the rigid shroud structure 408 that protects (includingthermal protection) the inflatable dummy target portion. By thisparticular embodiment the rigid warhead compartments forms part of thesecond stage but this form of rigid structure is not binding.

Turning now to FIGS. 5A-B, they illustrate schematically a dummy targetin wrapped and inflated forms, respectively, in accordance with certainembodiments of the invention. Thus, the dummy target in its wrappedposition is inflated (upon release see FIG. 5B) by gas originating froma known per se pressure vessel or gas generator 51. The gas inflates thedummy target such that its geometry 52 resembles that of the missile.

In accordance with certain embodiments the dummy target is devoid ofactive self inflation means (such as the specified gas generator), andtherefore the dummy target is inflated utilizing a source that isaccommodated in the carrier platform. By this embodiment, the inflatabledummy target is released in a wrapped form and is inflated e.g. by usinga passive inflating source such as passive pressure vessels (that apriori accumulate pressure or are charged through the carrier source.

A non limiting manner for achieving desired RF signature is by coatingthe skin of the dummy target with a proper material, thereby achievingRF signature that resembles that of the flying missile and thetemperature such that it manifests an IR signature that resembles thatof the flying missile. The dummy target skin may be heated by usingknown prior art methods like:

-   -   Chemical surface heating by known per se electrically activated        composition, which, upon activation, can generate a desired        temperature which extends for a pre-defined duration    -   Dummy target surface heating by the gas injected by gas        generator. In this case, in accordance with certain other        embodiments, there is employed another gas generator (not shown)        which is configured to serve as a backup for maintaining a        required temperature (for achieving the designated IR signature)        and for generating sufficient internal pressure so as to keep        the geometry of the dummy target substantially intact. The        invention is not bound by the number of gas generators that are        used.

The dummy target surface may be heated also by using sun power when theinterception test is performed in daylight conditions. The needed IRsignature can be achieved by using an appropriate coating layer of thedummy target skin.

In accordance with the embodiments described above, the dummy targetmanifests IR signature and/or RF signature and/or geometrycharacteristics that resemble those of the missile.

There follows a description in accordance with certain embodiments ofthe invention which concerns achieving exo-atmospheric flight dynamicsof the dummy target that substantially match that of the missile. Thus,attention is now drawn to FIGS. 6A-B, illustrating schematically frontand side views of a dummy target, serving for explaining dynamicequations, in accordance with an embodiment of the invention. As shown,in the side view of FIG. 6A, two nozzles are fitted in the dummy target(at locations 62 and 63). In response to ejection of gas from thespecified nozzles, two opposite forces F1 and F2 are applied to dummytarget 60 forcing a pitch movement of the dummy target about lateralaxis 61 (constituting the center of gravity of dummy target 60). Inaddition, and as shown in a front view of the dummy target 60 (FIG. 6B),two additional nozzles 65 and 66 force roll motion of the dummy targetin response to ejection of gas therethrough. By this example, the pitchmotion illustrated in FIG. 6A and the roll motion illustrated in FIG. 6Bgive rise to dummy target exo-atmospheric flight dynamics that shouldresemble those of the Ground to Ground missile. As will be explained indetail below, in accordance with certain embodiments, the gas pressureinside the dummy target and nozzle dimensions are exemplary parameterswhich are a priori designed to achieve the desired pitch and rollmotions.

FIG. 6C illustrates a lateral cross section of a nozzle, in accordancewith certain embodiments of the invention. The nozzles depicted in theembodiments of FIGS. 6B and 6C (e.g. 62 of FIG. 6A) may have the shapeas illustrated by way of example in FIG. 6C. Note that the invention isnot bound by the use of 2 nozzles per channel (i.e. pitch or roll) asdepicted by way of example with reference to FIGS. 6B and 6C. Inaccordance with certain embodiments, the number of nozzles in the rollchannel for the self-contained dummy target are at least two and thenumber of nozzles in the pitch channel is at least one.

In the case of using the carrier, capabilities as were noted above withreference to FIG. 4C, for inflating the gas, spin velocity (rollchannel) of the dummy target may be created by spinning of the carriersteering (ACS) 413.

Note also that the invention is not bound by the specific locations ofthe nozzles in the periphery of the dummy target. The invention islikewise not limited to the specific nozzle shape as depicted in FIG.6C. Other non limiting examples of nozzles are illustrated in FIG. 7Aand FIG. 7B.

Turning now to FIGS. 8 and 9, they illustrate schematically front 81 andside 82 views of a dummy target, serving for explaining dynamicequations, in accordance with an embodiment of the invention. FIGS. 9A-Billustrate sets of equations serving for explaining the dynamicsexo-atmospheric flight characteristics of a dummy target, in accordancewith certain embodiments of the invention.

Turning at first to the side view, it shows one nozzle fitted in thedummy target (at locations 83). Note that unlike FIG. 6, where twonozzles are depicted in the example of FIG. 8A, only one is depicted. Aswas explained above, the invention is not bound to the use of one or twonozzles. As shown, in response to ejection of gas from the specifiednozzle 83, a force F1 is applied to dummy target 80 forcing a pitchmovement of the dummy target about lateral axis 84 (constituting thecenter of gravity of dummy target 80). The pitch motion is around the Zaxis. Due to the symmetric shape of the dummy target, it moves in asimilar fashion about the Y axis. As will be explained in greater detailwith reference to the equations of FIG. 9 A (85 in FIG. 8A) the distancebetween the center of gravity and the nozzle is designated. P_(C) standsfor the gas pressure inside the dummy target. Turning now to FIG. 8B, itshows a front view of the dummy target. By this example (unlike FIG.6B), only one nozzle 86 is utilized, wherein in response to release ofgas through the nozzle, a force F2 is generated and applied to the dummytarget giving rise to roll motion about axis X. R (87) stands for theradius of lateral circular cross section of the dummy target thatcrosses the nozzle.

As will be explained below with reference to FIG. 9, the motion of thedummy target in the roll and pitch channels, gives rise to dummy targetexo-atmospheric flight dynamics that resemble those of the Ground toGround missile.

It should be noted that in order to achieve exo-atmospheric flightdynamics of the dummy target that resembles that of the missile, thedummy target should develop angular accelerations in the pitch channeland the roll channel that will give rise to corresponding angularvelocity which substantially matches that of the missile. Moreover, theangular accelerations (in the respective channels) should be dropped tosubstantially zero once the target velocities are achieved. Havingachieved the desired velocities (and eliminating the acceleration), thedummy target will maintain these angular pitch and roll velocities as itflies in space, thus achieving exo-atmospheric flight dynamics thatresemble those of the GTG missile. The set of equations described belowwith reference to FIGS. 9A and 9B will explain how to obtain desiredangular accelerations in the specified channels.

Bearing this in mind, attention is drawn to FIG. 9A, illustrating a setof equations serving for explaining the dynamics exo-atmospheric flightcharacteristics of a dummy target, in accordance with a certainembodiment of the invention. Thus, and as shown in equation 91, F standsfor the nozzle thrust (see e.g. F1 in FIG. 8A) and is calculated as theproduct of P_(C) (signifying the pressure in the closed volume of thedummy target, see e.g. FIG. 8A) 93, A_(exit) signifying Nozzle area (94)and a coefficient C_(f) 95 having a value of ˜1.2. Note that A_(exit) iseasily measurable and C_(f) is constant. The calculation of P_(C) isdiscussed in more detail with reference to FIG. 9B below, and,accordingly, F can be calculated.

The angular accelerations in the roll channel and the pitch channel (96and 97, respectively) are calculated as Inertial Moment M divided byInertia I. As shown, for example in equation 97, M is calculated as asummed product of F and l where the former is given in equation 91 (anddiscussed above) and the latter is a priori known (see 85 in FIG. 8A).The Σ over i sums i products of F and l, where i stands for the numberof nozzles. (In the embodiment of FIG. 8A only 1 nozzle is utilized). Inthe example of calculating angular acceleration in the pitch channel(equation 97), the relevant Inertia is along either the Y axis (orsymmetrically the Z axis) and therefore is designated in 97 as I_(YY).Note that I_(YY) is measurable in a well known manner to a person ofordinary skill in the art.

Similarly, in equation 96 (defining the angular acceleration in the rollchannel), M is calculated as a summed product of F and R where theformer is given in equation 91 (and discussed above) and the latter is apriori known (see 87 in FIG. 8B). The Σ over j sums j products of F andR, where j stands for the number of nozzles (by the embodiment of FIG.8B only 1 nozzle is utilized). In the example of calculating angularacceleration in the roll channel (equation 96), the relevant Inertia isalong the X axis (and therefore is designated in 97 as I_(XX). Note thatI_(xx) is measurable in a well known manner to a person versed in theart.

Moving on to FIG. 9B, there follows a description for calculating P_(C),which, as may be recalled, is required in order to determine F (seeequation 91).

Thus, P_(C) (t) is dependent upon a constant R (which is determined bypressure vessel or gas generator property), Gas temperature T 903 insidethe dummy target, VOL signifies the volume of the dummy target, m_(in)904 signifies the rate of flow per unit time generated by the pressurevessel or gas generator. This value is determined according to thegenerator specification. m_(out) 905, in its turn, stands for the rateof flow of the gas flowing out of the dummy target (through the nozzles)and complies with equation 906. Note that the parameters that affectm_(out) are Pc(t) which is determined iteratively (see 901), A_(exit)which is the nozzle's area, T standing for the gas temperature (see 901)and const that is determined by the geometry of the nozzle and the gasproperty.

It is thus appreciated that the number of nozzles (i and i), the area ofthe nozzle (A_(exit)), the Inertia I_(YY), I_(XX), gas temperature T,dummy target's volume VOL, nozzle location (relative to the center ofgravity) R and l, m_(out) (calculated based on the above parameters)and, m_(in) can all be determined in order to obtain the specifieddesired angular velocity in the pitch and roll channels.

Note also that there is an inherent behavior of the dummy target whichsupports the desired achievement of pitch and roll angular velocities.Thus, when the dummy target is ejected to space in a wrapped form, ithas a small moment of inertia around the three axes and due to a randomparasitic load resulting from the ejection process, the wrapped dummytarget manifests random angular velocities in the respective axes. Afterinflation, the moment of inertia dramatically increases (e.g. in about 3order of magnitude) and consequently the angular velocities in therespective axes are significantly reduced, thereby allowing to controlthe specified angular roll and pitch velocities, so as to achieve dummytarget exo-atmospheric flight dynamics that resemble that of the RV. Itis therefore appreciated that the specified process facilitatesobtaining desired dummy target exo-atmospheric flight dynamics (in thepitch and roll channels) notwithstanding the initial uncontrolledperturbations.

The required dynamic characteristics may be achieved also by using wellknown prior art flywheel mechanisms but their use seem problematic forpresent application because of relatively high weight consumption(flywheels and their power sources).

Note also (and as will be explained in greater detail below), that theinvention is not bound by the specified technique for generatingappropriate dummy target dynamics.

The exo-atmospheric Ground-to-Ground missile's interception trial hasbeen described with reference to non limiting embodiments of dummytargets as described with reference to FIGS. 5, 6, 7, 8 and 9. Therefollows a description with reference to FIG. 10 illustratingschematically a dummy target in accordance with another embodiment ofthe invention. Unlike the dummy target depicted in FIG. 5B, inaccordance with this embodiment, the dummy target is not an inflatablewhole object (see rear and side views in FIGS. 10B and 10D,respectively), but is rather composed of a chassis of inflatable ductse.g. 1000, 1001 which are inflated using e.g. a pressure vessel or a gasgenerator of the kind described above, installed at the dummy target orat the carrier. The pitch and roll dynamics may be achieved usingnozzles, e.g. 1002-1003 (in FIG. 10C) for the pitch and the 1004-1005(in FIG. 10A) for the roll to achieve dynamics that comply with thealgorithmic expressions discussed in detail with reference to FIGS. 8-9,mutatis mutandis. The ducts are wrapped with appropriate sheets (notshown) giving rise to a dummy target having a shape similar to thatdescribed with reference to the embodiments depicted above. The shape ofthe body achieves the desired geometry characteristics of the dummytarget, as discussed in detail above.

In certain embodiments, the dummy target can assume a cone shapedgeometry, e.g. to resemble a re-entry vehicle. In certain otherembodiments, the dummy target can assume a cylinder shaped geometry,e.g. to resemble a booster. In certain other embodiments, the dummytarget can assume a complex geometry made up of one or more conicaland/or frustoconical and/or cylindrical sections. Referring now to FIG.13A, there is illustrated non-limiting examples of a dummy target havinga cone shaped geometry 1301. Referring now to FIG. 13B, there isillustrated a dummy target having a cylinder shaped geometry 1303.Referring now to FIG. 13C, there is illustrated a dummy target having acomplex geometry composed of several sections including a conicalsection 1301 and a concave frustoconical section 1305. The dummy targetof FIG. 13C can be made to resemble, e.g. a body having a stabilizationskirt e.g. a re-entry vehicle. Referring now to FIG. 13D, there isillustrated a dummy target having a complex geometry composed of severalsections including a cylindrical section 1303 and a convex frustoconicalsection 1307. The dummy target of FIG. 13D can be made to resemble, e.g.a booster having a boat tail section. Referring now to FIG. 13E, thereis illustrated a dummy target having a complex geometry composed ofseveral sections including a conical section 1301, a cylindrical section1303, and two concave frustoconical sections 1305.

In certain embodiments, the chassis of inflatable ducts detailed aboveincludes one or more ducts made of a flexible, sealed and preferablylightweight material, e.g. polyamide or polyester based films like nylon66, mylar, etc. The flexible material allows the chassis to be foldedand packed in the carrier missile while occupying as little room aspossible prior to the dummy target being released from the carriermissile and the chassis inflated with a gas, as detailed above. Insteadof being inflated with a gas after deployment as detailed above, anotheroption is to seal a small amount of a gas in the inflatable ducts duringmanufacturing and no further inflation during deployment, since a smallamount of gas can allow the ducts to be folded or compressed in thecarrier missile (under atmospheric conditions), whilst still achievingthe desired dummy target geometry once released from the carrier missilein space, without requiring additional inflation.

The individual ducts that form the chassis can be interconnected to oneanother in any manner that, once inflated, supports the wrapping sheetin the desired dummy target geometry. Referring now to FIG. 14A, thereis illustrated a chassis of inflatable ducts arranged to support a coneshaped dummy target geometry when wrapped with a sheet (not shown) inwhich a ring shaped duct 1401 located at a base end of the chassis isconnected to one or more elongate ducts 1403 which extend therefrom andare angled inward and converge at an opposite apex end of the chassis.

Referring now to FIG. 14B, there is illustrated a chassis of inflatableducts arranged to support a cylinder shaped dummy target geometry, inwhich two ring shaped ducts 1401 located at opposite base ends of thechassis are interconnected by one or more elongate ducts 1403 extendingtherebetween.

Referring now to FIG. 14C, there is illustrated a chassis of inflatableducts arranged to support a frustoconical shaped dummy target section,in which two ring shaped ducts 1401 (one having a circumference greaterthan the other) are connected by elongate ducts 1403 extendingtherebetween.

It will be appreciated that various different combinations of ringshaped ducts and elongate ducts can be used to support a wide range ofaxi-symmetrical including concave or convex dummy target geometries.Referring now to FIG. 14 D, there is illustrated an embodiment of achassis of inflatable ducts incorporating additional elongate ducts 1404for rigidizing the inflatable dummy target. Ring shaped duct 1401 andelongate ducts 1403 are supported by the additional rigidizing ducts1404.

In certain embodiments, the wrapping sheet can be attached to the someof the ducts and not attached to other ducts. For example, in a coneshaped geometry, the wrapping sheet can be attached to the chassis atthe ring shaped duct and not attached to the elongate ducts except atthe apex. In a cylindrical shaped geometry, the wrapping sheet can beattached to the ring shaped ducts and not attached to the elongateducts.

In certain embodiments, the chassis of inflatable ducts can compriseducts of different diameters. In certain embodiments, a better targetgeometry is achieved if the ring shaped ducts have a larger diameterthan the elongate ducts, e.g. a non-distorted target geometry can beachieved, even when the wrapping sheet is not attached to the elongateducts (except at the apex in the case of a cone).

The RF signature is achieved by using a material that has RF signaturesimilar to that of the GTG missile (as discussed in detail withreference to the previous embodiments, above). As may be recalled in theprevious embodiments, the IR signature was achieved by using a surfacechemical heating by known per se electrically activated composition,which, upon activation, can generate a desired temperature which extendsfor a pre-defined duration by heating the dummy target surface by thegas injected inside the dummy target from gas generator, or by sun powerheating of the dummy target skin coated by an appropriate optical layer.The latter method is applicable for daylight test conditions.

The invention is not bound to the means for generating flight dynamicsin the manner specified above. Thus, in accordance with certain otherembodiments and as illustrated with reference to FIG. 11A-B, a flywheel1100 is fitted in the inflatable dummy target and is activated by amotor (not shown) at desired timing for rotating about axis 1101 (in adirection indicated by arrow 1102). As a result, the dummy target willrotate in an opposite direction (specified by arrow 1103) as stipulatedby the respective inertial moments ratio, all as known per se, so as toachieve the desired roll dynamics. Turning to FIG. 11B, pitch dynamicsare achieved by fitting a flywheel 1105 with a normal orientationrelative to flywheel 1100. Flywheel 1105 rotates about axis 1106 in adirection indicated by arrow 1107 to thereby achieve rotation of dummytarget in an opposite direction (specified by arrow 1108) as stipulatedby the respective inertial moments ratio, all as known per se, so as toachieve the desired pitch dynamics. In order to achieve angularacceleration (or deceleration) so as to achieve the appropriate pitchand roll dynamics, the flywheels are accelerated/decelerated using therespective motors, all as known per se. The placement of flywheels inthe manner specified, including the related motors and gimbals, isgenerally known per se and therefore not further expounded upon herein.

As may be recalled, the trial is in fact fully controlled since thelaunch timing of the carrier and the interceptor are fully controlled,and likewise also the release timing of the dummy target as well as thetiming of the interception and the location of the interception pointare all planned in advance. It is also noted that the operationalspecification of the interceptor are well known insofar as the minimaldistance from target that is required to sense IR signature areconcerned. In other words, when the interceptor is too far away from thetarget (by this embodiment the dummy target) it is insensitive to the IRsignature of the target. Accordingly, in accordance with certainembodiments, the dummy target's IR signature is activated only duringthe homing stage and the END GAME such that the interceptor can sensethe IR signature. With reference to the embodiment of FIG. 12, thismeans that the electrically operated heating composition is activated ata predefined timing when the interceptor is sufficiently close to sensethe IR signature of the target. This enables to activate the IRsignature generation means for only a limited period. This isillustrated in FIG. 12, which illustrates schematically an IR signatureactivation curve, in accordance with certain embodiments of theinvention. As shown, the IR signature is activated only at the homingstage and the END GAME 1200 (i.e. when the temperature rises). Whilstthe description with reference to FIG. 12 exemplified activation of theIR signature not throughout the entire exo-atmospheric flight session(i.e. through only a partial session, such as the homing stage and theEND GAME), the invention is not bound to activate only IR signaturethrough a partial exo-atmospheric flight session. Thus, othercharacteristics, such as RF signature and generating desired dummytarget dynamics may be activated through partial session such as thehoming stage and the END GAME.

As specified above, the carrier is capable of acquiring a sky view ofthe kill scene. In accordance with certain embodiments, this is achievedby utilizing the technique disclosed in WO 2006/025049 “a system andmethod for destroying a flying object”.

Those of ordinary skill in the art will readily appreciate that inaccordance with various embodiments of the invention there is provided amethod for simplifying exo-atmospheric Ground-to-Ground (GTG) missile'sinterception trial, that includes:

-   -   (a) providing at least one dummy target that is manufacturable        in a considerably simpler manufacturing process than a GTG        missile, and capable of manifesting characteristics that        resemble characteristics of the GTG missile;    -   (b) providing a common carrier missile capable of accommodating        at least one dummy target irrespective of the characteristics        thereof;    -   whereby said common carrier missile is capable of being launched        and being configured to release at least one dummy target at a        selected exo-atmospheric location, for testing the ability of an        interceptor missile to intercept said dummy target at an        exo-atmospheric interception point, thereby testing the        interceptor's operational feasibility to destroy the GTG        missile.    -   (c) providing kill assessment information from the kill scene        including achieved miss distance, angle of incidence etc.

As used herein, the phrase “for example,” “such as” and variants thereofdescribing exemplary implementations of the present invention areexemplary in nature and not limiting. Reference in the specification to“one embodiment”, “an embodiment”, “some embodiments”, “anotherembodiment”, “other embodiments” or variations thereof mean that aparticular feature, structure or characteristic described in connectionwith the embodiment(s) is included in at least one embodiment of theinvention. Thus the appearance of the phrase “one embodiment”, “anembodiment”, “some embodiments”, “another embodiment”, “otherembodiments” or variations thereof do not necessarily refer to the sameembodiment(s). It is appreciated that certain features of the invention,which are, for clarity, described in the context of separateembodiments, may also be provided in combination in a single embodiment.Conversely, various features of the invention, which are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any suitable sub-combination. While the invention hasbeen shown and described with respect to particular embodiments, it isnot thus limited. Numerous modifications, changes and improvementswithin the scope of the invention will now occur to the reader. Inembodiments of the invention, fewer, more and/or different stages thanthose shown in the drawings may be executed.

The present invention has been described with a certain degree ofparticularity, but those of ordinary skill in the art will readilyappreciate that various alterations and modifications may be carried outwithout departing from the scope of the following Claims.

1. An inflatable dummy target comprising a chassis of inflatable ductswrapped with a sheet.
 2. The inflatable dummy target of claim 1 whereinthe chassis of inflatable ducts comprises one or more ring shaped ductsand one or more elongate ducts wherein each ring shaped duct isconnected to at least one elongate duct.
 3. The inflatable dummy targetof claim 2 wherein the chassis of inflatable ducts comprises at leasttwo ring shaped ducts interconnected by one or more elongate ducts. 4.The inflatable dummy target of claim 2 wherein the dummy target geometryis conical shaped and the chassis of inflatable ducts comprises aring-shaped duct positioned at a base end of the chassis connected to aplurality of elongate ducts extending therefrom and angled inward andconverging at an apex end of the chassis.
 5. The inflatable dummy targetof claim 4, wherein the sheet is attached to the chassis only at thebase end and the apex.
 6. The inflatable dummy target of claim 4,wherein the chassis of inflatable ducts further comprises rigidizingducts.
 7. The inflatable dummy target of claim 2 wherein the dummytarget geometry is cylindrical shaped and the chassis of inflatableducts comprise a first ring shaped duct positioned at a first base end,a second ring shaped duct positioned at an opposite base end of thechassis, and a plurality of elongate ducts connected to the first andsecond ring shaped ducts and extending therebetween.
 8. The inflatabledummy target of claim 7, wherein the sheet is attached to the chassisonly at the base ends.
 9. The inflatable dummy target of claim 7,wherein the chassis of inflatable ducts further comprises rigidizingducts.
 10. The inflatable dummy target of claim 1 wherein the dummytarget is made of several attached axi-symmetrical sections, eachsection have a chassis of inflatable ducts.
 11. The inflatable dummytarget of claim 10 wherein the shape of each section is selected fromthe group consisting of conical, frustoconical and cylindrical.
 12. Theinflatable dummy target of claim 11 comprised of a conical sectionattached to frustoconical section, thereby achieving a concave dummytarget geometry.
 13. The inflatable dummy target of claim 11 comprisedof a cylindrical section attached to frustoconical section, therebyachieving a convex dummy target geometry.